Outreach at University of Texas Institute for Geophysics

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Earthquake in the Dominican Republic
22 September 2003

The Dominican Republic is shown within the black square. Santiago is located at the red star.
Location of the Dominican Republic in the Caribbean. Santiago is located at the red star.
(Topography and predicted bathymetry from Smith and Sandwell, 1997.)

At 11:45 pm on 22 September 2003, a M6.5 earthquake severely shook the northern Dominican Republic on the island of Hispaniola and caused extensive damage to buildings in the major cities of Puerto Plata and Santiago along with landsliding in outlying areas. In October 2003, Luis Pe�a, E. Vargas, J. Lockhart, and O. Franco, scientists from the Dominican Republic's Colegio Dominicano de Ingenieros, Arquitectos y Agrimensores (CODIA) invited U.S. geoscientists to install seismographs and resurvey GPS benchmarks in the northern area of the island affected by the earthquake.

A group headed up by Dr. Victor Huerfano and Ing. Jose Cancel (Puerto Rico Seismic Network - PRSN - of the University of Puerto Rico/Mayaguez) installed ten broadband seismograph stations (including CMG-40T seismometers) that were made available for this effort by IRIS PASSCAL through its Rapid Array Mobilization Program (RAMP). Efforts by Christa von Hillebrandt-Andrade, director of the PRSN, were key in arranging this support from IRIS. These stations will be installed in the Dominican Republic for at least 3 months although the group is now applying to the US National Science Foundation to extend their recording period and to fund analysis of these new data. Other members of this field group included Dr. Jay Pulliam (University of Texas Institute for Geophysics) and Ing. Eduardo Fajardo (CODIA and Office of the Govenor, Puerto Plata province).

Since their installation in mid-October, the broadband network has shown a nearly 100% data recovery rate including the recording of several large aftershocks related to the September 22 event. E. Fajardo is working in collaboration with the PRSN to maintain the broadband network.

Huerfano, Cancel, and Pulliam also met in mid-October with Dominican seismologists operating short period networks in the country: Ing. Luis Odonel-Gomez of the INDHRI and Ing. Juan Payero of the Universidad Autonoma de Santo Domingo. Both networks recorded the main shock of September 22, 2003, and its aftershocks and therefore provide a valuable record of the event. Discussions are underway between all these organizations to insure complete data sharing and collaborative efforts that include expansion of the broadband network into other parts of the country. This group also met with officials of the Universidad Catolica Madre y Maestra in Santiago about using their facilities for instrument installation as well as recruiting students to attend graduate school in earthquake seismology and earthquake engineering in the USA.

A second group headed up by Dr. Eric Calais (Purdue University) resurveyed 12 GPS sites in the area of the earthquake. This GPS effort is part of a longterm geodetic study of crustal motions in the Dominican Republic that was initiated in 1986. These GPS sites surround and include the epicentral area near Puerto Plata and will quantify crustal movements of the September 22 earthquake and its aftershocks. Other members of this field group included: Mr. Henry Turner, III, (PhD candidate in GPS-based geodesy from the University of Arkansas), Dr. Paul Mann (University of Texas Institute for Geophysics), Ing. Luis Pena (CODIA and Universidad Catolica Madre y Maestra, Santiago, Dominican Republic). GPS receivers were kindly provided by Dr. Pam Jansma and Dr. Glen Mattioli of the University of Arkansas. Collaboration and funding was provided by INDHRI and the Office of the Presidency.

A third group of Dominican scientists based at CODIA conducted regional surveys of damages. These CODIA reports are online at this website (see below).

Outreach efforts by this group in the Dominican Republic included a major press conference on October 18, 2003, at the CODIA office in Santiago that was well attended by both local scientists and the media. Dr. Mann spoke on "Preguntas y Respuestas Sobre el Terremoto Ocurrido el día 22 de Septiembre del 2003, en Puerto Plata, Rep. Dominicana" ("Questions and Answers On the Earthquake That Occurred 22 September 2003, in Puerto Plata, Dominican Republic"). Dr. Calais spoke on "Terremotos en Rep. Dominicana: Hechos Científicios y recomendaciones para la seguridad contra terremotos" ("Earthquakes in the Dominican Republic: Scientific facts and recommendations for the security against earthquakes"). Dr. Calais' talk presented the results of the joint efforts during the week-long discussions by Dominican Republican and U.S. scientists. These scientists have formed a working group to study the earthquake.

This GPS site (at right) on hilltop near La Vega, Dominican Republic, was reoccupied by P. Mann (UTIG) and L. Pena (CODIA) in October following the September 22 earthquake. This site has been occupied twice before over a period of four years. In the distance is the Cibao Valley and Cordillera Septentrional whose topographic front is defined by the active Septentrional strike-slip fault zone. This fault has not ruptured in 800 years and poses a major seismic hazard to the people living in the Cibao Valley.

Dr. Eric Calais (Purdue University) (at left) explained at a press conference at the CODIA auditorium in Santiago in October, 2003, how GPS data collected in October, 2003, can provide insights into the location and amount of slip on the fault that produced the September 22 earthquake. Ing. Jose Lockhart of CODIA translates. A copy of Dr. Calais' presentation is available at this website.

Dr. Victor Huerfano (University of Puerto Rico, Mayaguez) (at right) explained at a press conference in Santiago in October, 2003, how the IRIS broad band seismometers he helped to deploy in October, 2003, in the northern Dominican Republic can provide insights into the location and amount of slip on the fault that produced the September 22 earthquake.

About CODIA
Local seismic network of INDHRI
"Evaluación post-sismo en la Republica Dominicana, el 22 de Septiembre del 2003, lecciones aprendidas" ("Post-seismic evaluation in the Dominican Republic, 22 September 2003, lessons learned") - CODIA PDF^* file
"Evaluaciónes realizadas a edificaciones afectadas pro el sismo 22-Septiembre-2003 en Santiago" ("Realized evaluations and affected buildings by the 22 September 2003 earthquake in Santiago") - CODIA PDF^* file
"Informe de la evaluación de los da˜os ocasionados por el terremoto del 22 de Septiembre del 2003 al centro de comercio y de convenciones del Caribe. Santiago" ("Report of the evaluation of the damage caused by the earthquake of 22 September 2003 to the business and conventions center of the Caribbean. Santiago") - CODIA PDF^* file
Maps and documents from the Santiago Muncipal District (Ayuntamiento Muncipal de Santiago).
Dolan, J. and Bowman, D., 2004, Tectonic and seismological setting of the 22 September, 2003, Puerto Plata, Dominican Republic earthquake: Implications for earthquake hazard in northern Hispaniola, Seismological Research Letters, v. 75, no. 5, September/October, 2004.
"Earthquake shakes "big bend" region of North America-Caribbean boundary zone" (Mann, P., Calais, E., and Huerfano, V., 2004, EOS, Transactions AGU, vol. 85(8), pp. 77,83).